Contents
SSH connection with authentication using public key
Creation of public and private key pairs
Create a public/private key pair for a user connecting to the Linux server using OpenSSH.
Use ssh-keygen to create key pairs.
Creation of public/private key pairs is performed with remote login user privileges.
If you do not specify the destination and file name, id_ed25519 and id_ed25519.pub will be created in /home/(user name)/.ssh/. On the way, enter the password for the key.
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# su - huong [huong@Lepard ~]$ ssh-keygen -t ed25519 Generating public/private ed25519 key pair. Enter file in which to save the key (/home/huong/.ssh/id_ed25519): Created directory '/home/huong/.ssh'. Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/huong/.ssh/id_ed25519 Your public key has been saved in /home/huong/.ssh/id_ed25519.pub The key fingerprint is: SHA256:nyMTMTY7dRG3wjOpYWNetDJ52yxsMRDeF5AEYLfenKM huong@Lepard The key's randomart image is: +--[ED25519 256]--+ | o.=+*+o | | . o B.= o | | = % # o | | . @ & % | | S + X o | | + + o | | o E | | o . | | | +----[SHA256]-----+ |
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$ cat ~/.ssh/id_ed25519.pub >> ~/.ssh/authorized_keys $ chmod 600 ~/.ssh/authorized_keys $ chmod 700 ~/.ssh/ |
Save the created private key id_ed25519 to an appropriate location on windows using winSCP.
Start Winscp
Host name : Server IP Address
Port number : SSH Port
User name : Server Login User
Password : Password for the same user
and then "Save".
![](https://korodes.com/wp-content/uploads/2023/10/238359d247bbdf0b4db4e98d27c25348.png)
Site name : Any name
Click "OK"
![](https://korodes.com/wp-content/uploads/2024/03/6d0c3f64a9abfa4d8caaaeb5b95f51ab.png)
After confirming the server, click "Login".
![](https://korodes.com/wp-content/uploads/2024/03/459729e8124686e34db64d8dd5776fa8.png)
Click "Update" when the following screen appears
![](https://korodes.com/wp-content/uploads/2024/03/3deaa557d7506f5ea48551548a7e32bd.png)
Password of the logged-in user in the Password field
![](https://korodes.com/wp-content/uploads/2024/03/b0d6555b451ba239b81b3ebf9cd06df2.png)
When connected, the right column is the server side and the left column is the PC (Windows) side.
Save the file "id_ed25519" under /home/huong/.ssh on the server side to an appropriate location on Windows in the left column.
![](https://korodes.com/wp-content/uploads/2024/03/1efb09fee488a042082494fe57235b11.png)
Edit SSH configuration file
Edit the SSH configuration file to disable password authentication.
This time, instead of being an ordinary user, su - to become root.
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$ su - Password: # vi /etc/ssh/sshd_config # Line 66 : Change to password authentication disabled PasswordAuthentication no # systemctl restart sshd |
How to connect with Tera Term
Start Tera Term, and select "File" menu "New connection"
![](https://korodes.com/wp-content/uploads/2024/03/58091198d97317f2f81b754a0703223e.png)
Host : Server IP Address
TCP port : SSH Port number
![](https://korodes.com/wp-content/uploads/2023/10/af431d11475bca8e0062a978572e5d05.jpg)
If you get the following security warning "Replace...." and click "Continue".
![](https://korodes.com/wp-content/uploads/2024/04/8ddec1d665643287cf8112425863e453.png)
User name : Login User Name
Password : Password specified in the creation of a public/private key pair
Under "Use RSA/DSA/ECDSA/ED25519 key to log in", set "Private key file:" to "id_ed25519" that you just saved in Windows. and click "OK".
![](https://korodes.com/wp-content/uploads/2024/03/ad14d05d3394ec937ede695b99973767.png)
Creating a private key using PuTTYgen
Start Winscp, select the appropriate server, and "Run Puttygen" from "Tools".
![](https://korodes.com/wp-content/uploads/2024/03/519a22dc58064ad3f820a6f62966418d.png)
Click "Load"
![](https://korodes.com/wp-content/uploads/2024/03/a0883ea3bb7284908a4b9c98aa7f3d26.png)
Change the file type to [ All Files (*. *)] to read the private key id_ed25519 transferred from the Linux server.
![](https://korodes.com/wp-content/uploads/2024/03/20d4774cf04bf6f113b85cc844c03b97.png)
The password is the password set in "Creating a public and private key pair" above
![](https://korodes.com/wp-content/uploads/2024/03/7a2b703d3a8d5a72fe2419c543c40f31.png)
![](https://korodes.com/wp-content/uploads/2024/03/82decadb3e1fb84fc84992ac19080bfe.png)
Click on "Save private key"
![](https://korodes.com/wp-content/uploads/2024/03/6566461f260f266379278c9d7cb03fbc.png)
Save the file with the extension ".ppk" in the same place as "id_ed25519" saved earlier on the Windows side under the name "id_ed25519.ppk".
![](https://korodes.com/wp-content/uploads/2022/12/124caa7129db3a340bf3ea5bafeb5327.jpg)
Select the appropriate server and click "Edit"
![](https://korodes.com/wp-content/uploads/2024/03/26d9b84f3c52dcdfc30851bae32be01a.png)
Click on "Advanced"
![](https://korodes.com/wp-content/uploads/2024/03/ac3d7d4c018a5f75bcb39f90ffea5cb2.png)
Open the "Authentication" menu and specify "id_ed25519.ppk" saved in Windows for "Private key file"
![](https://korodes.com/wp-content/uploads/2024/03/dd44604c97d7d197b66f870eef468171.png)
Click "Save"
![](https://korodes.com/wp-content/uploads/2024/03/41b2e063d070630a394a3de59b655bf4.png)
Click on "Login"
![](https://korodes.com/wp-content/uploads/2024/03/06344ec6f5d5caa32230286fa0212a27.png)
The password is the password set in "Creating a public and private key pair" above
![](https://korodes.com/wp-content/uploads/2024/03/9e3dec3fc65f55d4869709427c801f5a.png)
When connecting with Tera Term
Use RSA/DSA/ECDSA/..." Specify "id_ed25519.ppk" saved in windows in the "id_ed25519.ppk" field.
![](https://korodes.com/wp-content/uploads/2024/03/494967822fb65c04f92bdf22b85b177c.png)